/Engine/Source/Runtime/Core/Public/Containers/BitArray.h
Pad this bit array with the specified value to ensure that it is at least the specified length. Does nothing ifNum()>= DesiredNum.
The number of bits that were added to the array, or 0 ifNum()>= DesiredNum.
int32 PadToNum ( int32 DesiredNum, bool bPadValue )